Sheepshead and drum are two different fish, yet they are in the same family. But down here they are saltwater fish. The sheepshead eats oysters, barnacles etc. They do have a set of teeth on them that could bite off a finger if you were careless, or ignorant.
Drum is a family of saltwater fish that contains...red drum (redfish), black drum, spotted seatrout, weakfish, and a couple others that I can't remember right now. The redfish has become quite a sport fish with several tournaments with large prize purses. There is a slot limit that could land you a small fine if you didn't know about it.